Telegraphic instrument.



J. J. GHEGAN.

TELEGRAPHIO INSTRUMENT.

7 APPLICATION mum mefas, 1908.

Patented July 6, 1909.

"UNITED STATES PATENT OFFICE.

JOHN J. GI'IEGAN, OF NEWARK, NEW ZIFITSFY, TO J. H. BUNNELL AND COMPANY, OF NEW YORK, N. Y., A CORPORATION OF NEW YORK.

TELEGRAPHIC INSTRUMENT.

To all whom it may concern:

Be it known that I, JOHN J GHEGAN, a citizen of the United States of America, residing in the city of Newark, in the county of Essex, in the State of New Jersey, have invented a certain new and useful Improved Telegraphic Instrument, of which the following is a specification.

The object of my invention is to provide a simple construction. of telegraphic instrument, particularly the telegraphic key, which may be used for either the open circuit system or the closed circuit system. This object I attain by the instrument which I will now describe and which is so constructed with a circuit closing switch that the manipulation of the key and its circuit closing switch are the same as in the closed circuit systems which are used so generally throughout this country.

My invention will be particularly advantageous to students whether in colleges or on private lines, as it will enable them to use dry cells for battery power when arranged for the open circuit work, while yet having their instruments always in circuit ready to receive as well as to transmit signals to a distance, but the battery is in use only when the key is being manipulated. With the ordinary closed circuit system, the battery is practically always in use, and on lines of low resistance, dry batteries would be rapidly and uselessly exhausted. The ordinary open circuit key is not provided with a circuit closing switch, familiarity with the use of which is very important to students, as will be readily understood by those versed in the art.

In the accompanying drawings, Figure 1 is a plan view of my instrument; Fig. 2 is a diagram illustrating the circuits, when the instrument is connected up for open circuit work; Fig. 3 is a similar diagram showing the closed circuit connections for the same instrument.

Referring to Fig. 1, the transmitting key, which with its connections forms the principal feature of my invention, has any usual or convenient form of metal frame F with usual or suitable adjustable bearings f for any usual or suitable key lever H, adapted to make contact with an insulated contact point 7, when the insulated knob f of the key lever is pressed. K is a circuit closing switch pivoted at 4 to the frame F, but in- Specification of Letters Patent.

Application filed August 25, 1908.

Patented July 6, 1909.

Serial No. 450,135.

sulated from the latter. When the switch lever K is moved to the right and in the position shown in Fig. 1, it makes electrical contact with the frame at 5. When the switch K is moved to the left, it makes contact with a contact piece 6, insulated from the frame The base board D, on which this transmitting key is mounted with a sounder S (represented conventionally, for the sake of simplicity), has three binding posts 1, 2 and 3. The post 1 is connected by wires under the base, as usual, to the sounder S, and from the latter runs a wire to the switch lever K at 41. The post 2 is connected to the insulated contact 6, while the post 3 is connected to the insulated contact 7. The line wire may be connected to the post 1, while post 2 is connected to line at mtermediate stations and to earth at terminal stations. If the instrument is to be used for open circuit work, the battery b is connected up be tween posts 2 and 3, as shown in Fig. 2, but Where it is to be used for closed circuit work, these posts 2 and 3 are connected directly with each other without batteries, while the line batteries G are connected at the terminal stations in the usual manner, such as between the posts 2 and the ground, Fig. 3.

The details of connections for a line for open circuit work will be understood u on reference to Fig. 2, which illustrates a Fine with three stations A, B and C. When any key is not in use for transmitting purposes, the switch lever K is moved over toward the transmitting lever (a manipulation the same as in closed circuit work on ordinary instruments) causing the lever K to contact with 6, and thereby closing the shunt around the key and battery I), as shown at the terminal stations A and C, Fig. 2. In this diagram, it is assumed that station 13 is transmitting, the switch lever K being thrown to the right to put the key lever II in circuit.

In Fig. 3 are shown diagrammatically the connections for using my instruments for closed circuit work, the change from the diagram, Fig. 2, being in the elimination of the batteries b and the direct connection of 2 to 3, and the insertion of line batteries G at the terminal stations. In this diagram also it is assumed that station B is transmitting.

In addition to the primary advantage of the above described instrument that it can be used interchangeably for either open circuit or closed circuit work, it has the advantage over the usual open circuit instrument that if any one happens to leave a book or other article of suiiicient weight upon the key, the circuit will not be closed thereby, as would be the case with the ordinary open circuit key. My instrument has the further advantage over the ordinary open circuit key that it requires only one pair of platinum contacts.

I claim as my inventionl. A telegraphic transmitting key, having a frame, a key lever and insulated contact for the latter, in combination with a switch lever insulated from the key lever, an insulated contact piece with which the switch lever may make connection in one position, the switch lever being adapted to make electrical connection with the transmitting key in its other position.

2. A telegraphic transmitting key, having a metallic frame, an electrically connected key lever and an insulated contact for the latter, in combination with a switch lever pivoted to the frame but insulated from it, an insulated contact with which the switch lever may make connection in one position, the switch lever being adapted to make electrical connection with the frame in its other position.

3. A telegraphic instrument, comprising a base board with three binding posts, a transmitting key, a switch lever and a key frame having three insulated points to which the three binding posts are respectively connected, one being the contact for the key, another being the switch lever and the third a contact piece for the switch lever, substantially as describe l.

In testimony whereof I have signed my name to this specification, in the presence of two subscribing witnesses.

JOIl\ J. GHEGAN.

W itnesses WM. H. BULL, J. WoRTsMANN. 

